Killer Subs in Pearl Harbor

The stealth attack of Pearl Harbor by Japanese midget submarines is a little known story of WWII.
Airing May 23, 2012 at 9 pm on PBS
Aired May 23, 2012 on PBS

Originally aired 01.05.10

Program Description

(Program not available for streaming.) NOVA dives beneath the waters of Pearl Harbor to trace provocative new clues to one of the most tragic events of World War II—the sinking of the USS Arizona. More than 1,000 crew members perished in the greatest single loss of life in United States naval history. For decades, it has been thought that a bomb dropped by a Japanese aircraft sank the Arizona. But the discovery of a group of Japanese midget subs in and around Pearl Harbor has raised questions about the battleship's final hours.

NOVA's team of expert investigators journey to the seafloor to explore the wreckage of the most mysterious of these subs. Did this mini-sub and its two-person crew make it into Pearl Harbor and fire torpedoes at the Arizona? They pursue this puzzle with unprecedented access to the remains of the Arizona and other unique evidence, including aerial photos taken by Japanese aircraft and moving testimonials from U.S. and Japanese veterans. "Killer Subs in Pearl Harbor" is a gripping investigation of the possibility that these tiny but lethal mini-subs may have played a crucial and previously unsuspected part in the tragic events of that "Day of Infamy."

Transcript

Killer Subs in Pearl Harbor

NARRATOR: An expedition is underway, and it may rewrite the
history of the Japanese attack on Pearl Harbor, a day that forever lives in
infamy.

FRANKLIN ROOSEVELT (President
of the United States, 1933–1945, Radio Address): ...December 7th, 1941, the United States of America
was suddenly and deliberately attacked.

JOHN CHATTERTON (Wreck
Diving Expert): This is the
exact moment when the United States was drawn into World War II. You would
think that we would know just about everything about this attack. We don't.

NARRATOR: Most people think of the surprise attack on Pearl
Harbor as an aerial assault raining down from the sky. But now the mysterious
wreck of a Japanese submarine, missing for almost 70 years, has been found in
the waters just outside Pearl Harbor. Could the attack have also come from
below?

PARKS STEPHENSON (Marine
Forensic Historian: It's almost
like a C.S.I. situation, when you have a crime scene.

NARRATOR: Can forensic science unlock the secrets of the
mystery sub and reveal the true story of the attack on Pearl Harbor?

DANIEL MARTINEZ (Historian,
National Parks Service): Pearl
Harbor is wrapped in enigma and mystery, and somewhere is the truth.

NARRATOR: Killer Subs in Pearl Harbor,
next on NOVA.

NARRATOR: Oahu: One of the Hawaiian Islands; a vacation
paradise in the Pacific; spectacular vistas, tropical beaches and vivid
reminders of the past.

For a few hours, early on December 7th, 1941,
this little piece of heaven became a living hell.

The sky, that Sunday morning, blazed in the
crossfire of a fierce aerial assault: more than 350 Japanese aircraft bombing
and blasting the American Pacific Fleet berthed in Pearl Harbor; dive-bombers
strafing people, planes and structures on the shore.

The surprise attack shook not only the entire
harbor, but also an entire nation that suddenly found itself at war. Over 2,400
Americans lost their lives in the battle. Almost half of them died on just one
ship, the U.S.S. Arizona.

It remains under the sea, a powerful symbol of a
devastating day.

Today a monument is built on top of the wreck.
Over a million people visit each year and pay their respects to the 1,177 men,
most of whom remain entombed inside the hull of the Arizona below, a sunken,
600-foot-long steel coffin.

Don Stratton was on the Arizona, directing
anti-aircraft guns at incoming planes, when the ship caught fire and sank.

DONALD G. STRATTON (U.S.S.
Arizona Survivor): My hair was
burned off; I lost part of my nose, part of my ear; my back was burnt; both my
legs are burnt. It was just a hell of a day, but I don't talk about it that
much, so that's all I've got to say about that.

NARRATOR: But there was another part of the Japanese
offensive completely hidden from view.

AKIRA IRIYE (Harvard
University): ...popular perception
is that the Pearl Harbor attack was primarily an aerial attack, coming from the
sky.

EDWARD T. O'DONNELL
(College of the Holy Cross): It's
the ultimate air raid, but a closer look at the battle of Pearl Harbor really
reveals that there's a lot more to it than that. It also tells us a lot about
the Japanese expectations that they really wanted to completely cripple the
Pacific Fleet.

NARRATOR: Compelling evidence now suggests that Pearl
Harbor was attacked not only from above, but below.

Hours before Japanese aircraft carriers launched
their planes from a position north of Oahu, a secret weapon was already
approaching from the south.

According to military records, shortly after
midnight, five Japanese submarines slipped undetected to within just a few
miles of Pearl Harbor,

each one carrying a technological marvel on its
back: a two-man midget sub.

The five Type A midget submarines were about a
quarter the length of the mother sub. Just six feet wide and packed with
equipment, these miniature subs were designed for efficiency, not comfort.

A 600-horsepower electric motor propelled the
midget subs swiftly under water at 19 knots, twice as fast as many other World
War II submarines. The midget subs could not only take the enemy by surprise,
they could hit the enemy hard.

The bow of a midget sub on display at the Naval
Academy in Japan shows how.

NARRATOR: Just one of these modified Long Lance torpedoes
could punch a hole in a towering battleship.

The Japanese built hundreds of midget submarines
during World War II and deployed them all across the Pacific and Indian Oceans.

The surprise attack on Pearl Harbor would be the
midget sub's opening act for the war that followed.

Author Burl Burlingame has investigated their
top-secret operation.

BURL BURLINGAME
(Author, Advance Force-Pearl Harbor): The midget submarines were supposed to get in the
harbor, lie low, wait for the attack to happen, and then surface, fire their
torpedoes into the American ships, attacking them from the bottom as well as
from the top.

NARRATOR: But how well did the plan succeed?

We know that four of the five midget subs
launched that morning failed in their mission.

BURL BURLINGAME: One
midget submarine was sunk before the attack. It did not fire its torpedoes.

NARRATOR: Midget sub number 1 was shelled by the U.S.S.
Ward, over an hour before the Japanese warplanes attacked.

It remains where it sank, just outside the
harbor.

Midget
sub number 2 entered Pearl Harbor, but after missing its target with both
torpedoes, the sub was destroyed by a pair of American ships. It was raised two
weeks after the attack and buried as landfill.

Two down, and another two would never make it
even close to the harbor.

Midget sub number 3 ran aground on the east side
of Oahu,

and its captain became the first Japanese
prisoner of war. Neither of its torpedoes had been fired.

It is now on display at the National Museum of
the Pacific War, in Texas.

The fourth midget sub turned up years later,
several miles south of Pearl Harbor.

BURL BURLINGAME: Another
midget submarine was found in 1960, at Keehi Lagoon, and it still had its
torpedoes in it.

That midget submarine was shipped back to Japan.

NARRATOR: It now stands outside the Naval Academy in
Etajima.

EDWARD O'DONNELL: It's
pretty clear that four of the submarines did not actually complete their
mission.

NARRATOR: What about number 5, the last of the midget subs?

PARKS STEPHENSON: The
fifth one was a mystery. Historians differed on what it could have done, or
where it could've ended up.

NARRATOR: We know that midget sub number 5 began its
journey in Kure, Japan. Petty Officer Kichiji Dewa was aboard its mother sub
the night number 5 launched into battle. Dewa recorded his thoughts in a secret
diary.

KICHIJI DEWA (Imperial
Japanese Navy, Retired): After
long days of waiting, X Day has come. The crew were dressed in clean clothes
and prepared.

NARRATOR: During the war, the Japanese were told that the
fifth midget sub had scored a devastating kill.

BURL BURLINGAME: The
Japanese midget submariners became the heroes of the attack, in Japan. They
were given credit for sinking the U.S.S. Arizona.

NARRATOR: Did midget sub number 5 sink the Arizona or any
other American battleship that day in Pearl Harbor?

DANIEL MARTINEZ: I
think that a cat and mouse game is still going on, with historians trying to
find out what happened to the fifth sub.

NARRATOR: Now, after almost 70 years, the mystery may be
solved and the true story of the attack on Pearl Harbor finally revealed.

Terry
Kerby is a submersible pilot who has been exploring the ocean floor around the
Hawaiian Islands for years. The area just outside of Pearl Harbor is an
underwater museum of World War II debris.

TERRY KERBY (Director
of Operations, National Oceanic and Atmospheric Administration/Hawaii Undersea Research
Lab): We found wrecks of
airplanes and vehicles and pier parts and lots of junk.

NARRATOR: During a routine test dive, three miles south of
Pearl Harbor, Terry spotted something unusual.

TERRY KERBY: That's definitely a conning tower sticking up.

NARRATOR: It was a long tube of steel, and to an expert eye
it resembled part of a Japanese midget sub.

Terry
eventually found two more sections spread out across the ocean floor. But are
all three pieces from the same submarine? And if so, is it the wreck of midget
sub number 5, missing since December 7th, 1941?

NOVA has assembled a unique team of investigators
to find out. They come from both sides of the battle: America and Japan.

Leading the investigation is marine forensic
historian, Parks Stephenson, a former U.S. Navy officer and submariner.

PARKS STEPHENSON: Today's
the day. After months of study, we are actually going down to the wreck of the
midget sub that we've identified as potentially the last of the missing
Japanese midget subs that participated in the attack on Pearl Harbor.

NARRATOR: Joining Parks is Admiral Kazuo Ueda.

PARKS STEPHENSON: I
was honored that Admiral Ueda offered to come out here. He was the senior
surviving midget submariner from the war. No one knows the whole context of the
Japanese midget subs better than he.

NARRATOR: Admiral Ueda has his doubts about the midget sub.

He doesn't think it's midget sub number 5, but
one damaged and dumped by American forces later in the war.

Historian Go Okumoto knows midget subs from the
inside out.

PARKS STEPHENSON: He
wrote a book on the midget submarines, he's probably the premier Japanese
expert.

NARRATOR: Go wants to study the wreck before drawing any
conclusions.

The Japanese built hundreds of midget subs during
the war.

BURL BURLINGAME: One
of the few things we know about the midget submarines as a class of submarines
is that the, the Japanese navy was always tinkering with them.

NARRATOR: The five midget subs deployed at Pearl Harbor
were early models and unlike any that followed.

The team plans to dive over a thousand feet below
the surface in two deep-sea research submersibles, the Pisces IV and the Pisces
V.

Admiral Ueda will dive in the Pisces IV.

Go joins Parks Stephenson in the Pisces V, with
Terry Kerby at the controls.

Just big enough for a three-person crew, the submersibles can dive to
a depth of over a mile and stay down for up to 10 hours.

Equipped with instruments to monitor the ocean
and collect samples, the Pisces IV and the Pisces V are state-of-the-art midget
submarines. But they're tools of science, not weapons of war, entirely
different from the Japanese midget subs of 1941.

Even though Terry's been down here before,
doesn't mean the sub is easy to find.

After searching for over an hour, the crew sees
some World War II wreckage.

PARKS STEPHENSON: We
have come across what appears to be an upside-down amphibious track vehicle.
Looks like there's been damage to the underside of it.

NARRATOR: These are the wrecks of several amphibious
assault vehicles, but nestled among them...

TERRY KERBY: Okay, we've got something coming up here.

NARRATOR: ...what, at first glance, could be a torpedo, is
actually the stern of a Japanese midget submarine.

The size and shape are unmistakable to historian
Go Okumoto. To learn more, he and Parks want to examine the rudder, the moveable
fin that steers the sub.

PARKS STEPHENSON: We
want to see the rudders. We're going to try and match the rudders to that
single screw guard.

NARRATOR: The rudder design on the five subs sent to Pearl
Harbor was never used again. That's because it was a liability.

MASANORI ANDOU: The
rudder is very small in proportion to the body of the ship. This means that it
is not very powerful. This makes it necessary for the sub to have a large
turning radius.

NARRATOR: After Pearl Harbor, the Japanese would change the
rudder design to make the midget subs more maneuverable.

The Pisces V moves in for a closer look.

TERRY KERBY: So this looks like it landed on its tail. It's kind
of crumpled up a bit.

NARRATOR: Though the stern is badly damaged, the rudder on
its back is still visible.

PARKS STEPHENSON: We
still do see the small thin rudders. Based on that, again, this is consistent
with a Pearl Harbor submarine.

NARRATOR: One piece of the puzzle may be in place, but a
cable dangling from the stern doesn't quite fit.

PARKS STEPHENSON: What's
that curved piece of metal over to the left? Is that a cable or...

TERRY KERBY: That's a cable.

NARRATOR: Go believes this cable is completely out of place
and not part of any Pearl Harbor midget sub.

TERRY KERBY: Pisces IV, we're moving on.

MAX CREMER: Roger, go ahead.

NARRATOR: Terry Kerby steers the Pisces V toward the second
piece of the wreck, as the Pisces IV follows.

Before the war, the American military knew almost
nothing about these midget subs. They were the Japanese navy's most guarded
secret weapon.

BURL BURLINGAME: We
simply didn't know about these midget submarines. And when they appeared at
Pearl Harbor, they actually caused quite a stir.

NARRATOR: The December 7th attack turned out to be not only
a military surprise but also a technological one.

Other countries were developing midget subs, but
they were mostly human-guided torpedoes; crude, unreliable and often suicide
weapons.

PROFESSOR HARUO TOHMATSU (National Defense Academy of Japan): Technically speaking, the Japanese midget subs were
far superior to their counterparts produced by British, German or Italian navies.

NARRATOR: The Japanese versions were more like real
submarines, but much more compact.

BURL BURLINGAME: They
were able to miniaturize the propulsion technology and use batteries.

NARRATOR: The midget sub made ingenious use of its limited
space. Divided into seven compartments, both pilot and captain operated inside
a control room the size of a closet, crammed with switches, instruments and a
radio-telegraph.

These cleverly designed machines were constructed
in a closely guarded plant, in three separate sections, almost the same way the
mystery sub would be found decades later.

Terry Kerby maneuvers into position next to what
appears to be the midsection of a Japanese midget sub.

KAZOU UEDA:
It is much different than I expected. The
sub is quite wrecked.

NARRATOR: Parks and Go are looking for a pulley.

The mouth of Pearl Harbor was protected by
anti-torpedo nets, so the midget subs had net-cutters attached to the bow. A
cable was installed, with a pulley, to guide the net up and over the sub so it
wouldn't get caught.

At first they can't see it. Then...

TERRY KERBY: Alright, so there's the tensioning pulley.

NARRATOR: After Pearl Harbor, both pulley and cable were
modified. According to historian Go Okumoto, this pulley looks like it belongs
on a Pearl Harbor midget sub.

Yet with each new clue comes another puzzle.

They find a mysterious cable attached to the
midsection, just like the one on the stern.

But there's still one more piece to examine.

TERRY KERBY: Roger, can you give us direction and range to the
bow section? Over.

NARRATOR: The sharp-edged net-cutters attached to the bow
of the five Pearl Harbor midget submarines were unique. Unlike any others that
followed, they were shaped like a figure eight.

BURL BURLINGAME: After the Pearl Harbor attack, it was
assumed that the midget submarines had trouble getting through our nets, so
they added these great big net-cutters that looked like something out of a
Jules Verne novel.

NARRATOR: The figure-eight net-cutter is key to identifying
midget sub number 5.

TERRY KERBY: The current has put us into position.

NARRATOR: The Pisces submersibles move in on the bow.

PARKS STEPHENSON: There
it is, right frickin' there.

NARRATOR: Admiral Ueda confirms the discovery.

ADMIRAL KAZUO UEDA (Japan
Maritime Self-Defense Force): It
is in the shape of a number eight. One can conclude definitely that this was
the special submarine that was used in Pearl Harbor.

NARRATOR: Go Okumoto agrees.

GO OKUMOTO (Historian
and Author): This is the last of
the midget sub.

PARKS STEPHENSON: This
is the last of the midget subs.

NARRATOR: Out of sight at the bottom of the sea for almost
70 years, midget sub number 5 has at last been found.

A giant piece of the Pearl Harbor puzzle has
fallen into place.

And now, the key question can perhaps be
answered. We know that none of the other midget subs successfully fired their
torpedoes inside Pearl Harbor. But unlike the other four, did midget sub number
5 fire its torpedoes into a battleship?

HARUO TOHMATSU: The
navy high command actually believed that it heavily damaged or sunk one
American battleship at Pearl Harbor.

NARRATOR: Japanese war records reveal that shortly after
midnight on December 7, 1941, midget sub number 5 surfaced seven miles outside
of Pearl Harbor on the back of its mother sub.

As the mother sub slowly descended for the
launch, the two-man crew of number 5 was ready for action.

Pilot Sadamu Kamita sent a final letter to his
parents: "Should anything happen to me, do not grieve, for I have dedicated my
life in service to His Imperial Majesty."

Years earlier, Commander Masaji Yokoyama had
written four words on his naval academy notebook, "vigor, spirit, patience" and
"honesty." Both men would need these attributes in the hours ahead.

Petty Officer Kichiji Dewa recalls that Kamita
and Yokoyama were highly qualified for the job.

KICHIJI DEWA: They were specially selected who proved to be at the
top of their class.

We
were more than brothers. Especially, for midget submarines, it is something
that deals with life and death.

NARRATOR: Dewa was the last person to speak with the crew.

KICHIJI DEWA: Before going off to attack, the captain of the
midget submarine said, "Thank you for your maintenance work." The only response
I could give him was, "Please take care, and good luck."

NARRATOR: With that, the two submarines pulled apart. The mother
sub remained at sea, while number 5 headed straight for the mouth of Pearl
Harbor.

But did it do any harm?

The camera on Pisces V is able to peer right
inside the torpedo tubes. Both of them are empty.

PARKS STEPHENSON: We're
right at the business end of the bow section of the midget submarine, staring
right down the empty torpedo tubes. It's an amazing sight.

NARRATOR: But if midget sub number 5 succeeded in firing
its torpedoes, did they find their target?

Around 10:40 p.m., some 12 hours after the
attack, Petty Officer Dewa received a message in Morse code from midget sub
number 5: the Japanese characters "ki ra," a message that made no sense. Dewa
thinks the exhausted crew made a mistake.

KICHIJI DEWA: Yokoyama's sub wanted to send the signal "tora," but
I think they mistakenly sent "ki ra" instead.

NARRATOR: "Tora" begins with a dot, dot. "Ki Ra" begins
with a dash, dot. All it takes is an extra second on the clicker to turn a dot
into a dash.

KICHIJI DEWA: Their hand might have slipped.

NARRATOR: Tora was a Japanese code word.

KICHIJI DEWA: The airplanes that flew to Hawaii sent the same
signal "Tora, tora, tora."

NARRATOR: It meant, "We have succeeded in our surprise
attack."

The mother sub sent word to the Japanese high
command, where the report of success was taken as fact. In their absence, the
midget submariners were accorded the highest honors.

HARUO TOHMATSU: During
the war time, these midget sub crews were regarded as hero gods.

BURL BURLINGAME: ...which
is sort of like in between human and God. And they, they sold posters of them. They
were sort of like the rock stars of, of World War II Japan.

DANIEL MARTINEZ: The
Japanese media embraced the idea that these men had sacrificed everything for
the nation, made a film about them.

BURL BURLINGAME: They
had books written about them. The midget submariners were given vast amounts of,
of credit for, for the success of the attack.

NARRATOR: And for Petty Officer Dewa, who had come to know
the crew of number 5, the message had a special meaning.

KICHIJI DEWA: "They did it!" That's what I felt. We were eagerly
waiting for the news of success. When we finally received it, I realized our
success.

NARRATOR: The two empty torpedo tubes appear to support
that success.

But just because the tubes are empty doesn't mean
the torpedoes were fired. Perhaps they were removed?

He sends all the information to microbial
ecologist Lori Johnston, an expert in what happens to metals under water.

Even
though the encrustation on the torpedo tubes looks like rust, it's not.
Ordinary rust is a purely chemical reaction. This is something entirely
different, known as a "rusticle."

LORI JOHNSTON: A rusticle is a living organism. It's actually
bacteria, micro-organisms that are naturally found in the environment.

NARRATOR: Also found on the wreck of the Titanic, rusticles
feed on metal in salt water.

LORI JOHNSTON: This is an example of a rusticle. It's full of
little crevices and cracks and tunnels. You're not dealing with one type of
bacteria, you're dealing with multiple types of bacteria: a "consorm," or a
consortium of bacteria.

Each different tunnel has different types of
bacteria working together. That's why they are so good at being able to break
down steel. Any types of metal, any types of nutrients, they're able to
incorporate that within the rusticle structure.

NARRATOR: Bacteria most likely would have started breaking
down midget sub number 5 soon after it sank.

LORI JOHNSTON: Once the sub has been in the water for a very short
period of time, within weeks and months, encrustation has already started to
form.

So it's almost like cementing the torpedo within the
tube.

NARRATOR: That would make it extremely dangerous to remove.

LORI JOHNSTON: It would be taking your life in your own hands by
removing an active, a live torpedo that had started to cement in the tube.

NARRATOR: Lori believes all the evidence points in a single
direction.

PARKS STEPHENSON: So
you are 100 percent confident that the Arizona received one or more torpedoes
during the attack.

ARNOLD BAUER (U.S.S.
Vestal Survivor): Yup, I saw the
track.

PARKS STEPHENSON: Okay,
so you were standing here, on the quarterdeck.

ARNOLD BAUER: And I went over on this side to see what was going
to happen to this side.

PARKS STEPHENSON: Why
did you go running over here?

ARNOLD BAUER: Because I figured if a torpedo was going to hit
here, I wanted to be on the other side.

NARRATOR: On the morning of December 7th, 1941, Don Stratton
was defending the Arizona from incoming fire, and he remembers a pair of
torpedoes heading towards the ship.

DON STRATTON: I swear, to this day, that two of them were headed
right toward the Arizona and the Vestal.

PARKS STEPHENSON: For
those people who say that the Arizona definitely wasn't torpedoed, what do you
have to say to them?

DON STRATTON: They weren't there.

PARKS STEPHENSON: But
you saw them.

DON STRATTON: I saw them, for sure.

NARRATOR: But after hours of searching, Matt Russell and
John Chatterton can't find any evidence of a torpedo hit.

JOHN CHATTERTON: We've
gone over virtually every inch of the port side of Arizona's bow. We don't see
anything that would indicate damage from a torpedo.

NARRATOR: But what if that torpedo was a dud?

Anti-submarine expert Tom Taylor has uncovered an
obscure passage in a Congressional report by Admiral Nimitz, Commander of the
Pacific Fleet.

It describes an unexploded torpedo sighted inside
Pearl Harbor, one that may have come from midget sub number 5.

TOM TAYLOR (United States
Navy, Retired): At the end of
one of the paragraphs, it states a recovered, unexploded torpedo carried an
explosive charge of 1,000 pounds.

We
knew that the aerial torpedoes were only around 500 pounds.

PARKS STEPHENSON: That
could only be a submarine torpedo. The aerial torpedoes were less than half
that charge.

TOM TAYLOR: The fact that he reported that they recovered this
torpedo indicates corroborating evidence that a midget sub had penetrated
Battleship Row and had fired upon it.

NARRATOR: We will never know if that torpedo was intended
for the U.S.S. Arizona, but if it was a dud, that still leaves one more torpedo
unaccounted for. On the morning of the attack, the U.S.S. West Virginia and the
U.S.S. Oklahoma were forward of the Arizona on Battleship Row.

Two naval experts believe they have found a
photograph of midget sub number 5 in action against at least one of them.

Recovered after the war, this picture was taken
by a camera on a Japanese plane the morning of December 7th.

It's fuzzy and unclear, but some experts believe
it's a midget sub firing a torpedo straight into Battleship Row.

Naval intelligence officer John Rodgaard and
forensic engineer Peter K. Hsu have spent years analyzing this single
photograph.

CAPTAIN JOHN RODGAARD
(United States Navy): What we
see in this photo is the effects of the initial aerial torpedo strikes against Battleship
Row.

We
can see the concussion waves radiating out from the ships that have been hit.
We can see torpedo tracks in the water. We see an object in the water with a
distinctive horizontal feature and a distinctive vertical feature.

NARRATOR: Both are features of a midget submarine.

JOHN RODGAARD: The
vertical feature would be the sail, the horizontal feature, the hull. We can
see behind it, plumes of water caused by a propeller.

PARKS STEPHENSON: Could
those plumes of water be caused by a torpedo being dropped by an airplane?

JOHN RODGAARD: No
because a torpedo hitting the water has a distinctive splash. It is a forward
movement. This does not have that characteristic. It is more of a fountain
effect, caused by a propeller.

NARRATOR: The propeller of midget sub number 5.

Whenever a Japanese midget sub fires a torpedo,
there's a sudden loss of balance.

MASANORI ANDO: A
torpedo weighs about one ton; the sub weighs 46 tons. When a torpedo is
launched, the forward part suddenly gets one ton lighter.

NARRATOR: ...which, in turn, rocks the sub up and down as the
crew struggles to regain control.

This creates a unique plume of water called a
rooster tail, which occurs when the propeller flies out of the water.

But did the torpedo hit its target?

The rooster tails in the photograph could offer a
clue.

According to Hsu, an expert in fluid dynamics,
one of these rooster tails may also be the result of the midget sub torpedo
hitting its mark.

Under John and Peter's guidance, NOVA has taken
the team's original classified calculations and re-engineered them into
revealing animation.

When a torpedo blasts into a ship, it produces a
shockwave powerful enough to lift a sub out of the sea, even at a distance. The
shockwave created by an airborne torpedo isn't powerful enough to reach the
midget sub.

PETER HSU (Forensic
Engineer, United States Navy): The
area generated by the shockwave does not reach the submarine.

NARRATOR: Because a torpedo fired by a midget sub has a
warhead almost twice the size as an airborne one, the shockwave it creates
radiates much farther.

And when that torpedo hits its target...

JOHN RODGAARD: Cavitation
extends beyond the submarine and lifts it above the surface.

NARRATOR: But how does the animation compare with the
original photograph?

JOHN RODGAARD: What
we see in the animation is the effect of the explosion on both the submarine
and the large rooster tail—as we can see—as a snapshot in time of
the large plume behind the submarine, in the photograph, and the plume rising
alongside the West Virginia, and the correlation is perfect.

NARRATOR: The West Virginia took at least seven torpedo
hits.

The Oklahoma was hit by up to nine torpedoes.

While most were launched from planes, Rodgaard
and Hsu believe that two of those torpedoes were fired by midget sub number 5.

JOHN RODGAARD: ...one
striking the West Virginia, the other one appearing to move towards the
Oklahoma.

NARRATOR: This leaves us with conflicting conclusions. If
the accounts of some eyewitnesses and the Nimitz report are to be believed, one
torpedo was fired at the Arizona but turned out to be a dud.

If the photographic experts are to be believed,
then two torpedoes were fired, hitting the West Virginia and the Oklahoma.
Either way it appears likely that midget sub number 5 successfully fired its
torpedoes inside Pearl Harbor.

So after completing its mission where did it go?

DANIEL MARTINEZ: We
actively know, through documents and through primary source photographs, that
there was a hunt for these submarines. The chances of one getting out, I think,
is extremely narrow.

NARRATOR: During the attack, a U.S. naval minesweeper
reported both sighting and firing upon what appeared to be a midget submarine
trying to escape the harbor.

KICHIJI DEWA: They had nautical charts of Hawaii in their hand; they
had the basic map of inner harbor memorized in their head.

DANIEL MARTINEZ: Where
would the sub go? What was safe?

NARRATOR: Parks Stephenson examines a Japanese map from one
of the recovered midget subs.

PARKS STEPHENSON: So,
if I'm looking at this chart, and I seem to be running out of options, there's
this area here which is open and, according to this Japanese legend over here
on the side, the West Loch doesn't have a whole lot in it.

NARRATOR: Parks believes number 5 escaped to the relative
isolation of the West Loch, at the time, a backwater fueling area.

But what happened to the sub and its crew,
Commander Masaji Yokoyama and Pilot Sadamu Kamita?

During the investigation of the wreck, the team
discovered what could be a frightening clue.

About 10 feet of the sub appears to be missing.

PARKS STEPHENSON: If
you look at the edges of this torn steel here, it's bent outward. Whatever did
the damage back here came from inside the sub.

NARRATOR: In order to keep Japan's secret weapon out of
enemy hands the crew was instructed to escape if they could, but to destroy
their submarine by igniting a scuttling charge lashed to the midsection.

Did Yokoyama and Kamita follow these
instructions? And if so, how?

NOVA has recruited a team of experts to find out.
If the two men scuttled their sub on the surface, they could have lit the fuse
and possibly escaped with their lives. If the crew was submerged, then the crew
is probably still sealed inside.

Naval Engineer Roger Long has created a scale
model of a midget submarine from an old scuba tank.

Demolitions expert David Loring is in charge of
the action.

DAVID LORING (Demolitions
Expert, United States Navy): This
is Naval Weapons Station Earle E.O.D. demolition range, about 11,000 acres of
bombs and bullets.

ROGER LONG(Engineer,
United States Navy): And we're
going to test it on the surface, with this open, as if they set off the
scuttling charge floating, and then we're going to explode under water with a
plastic cap to simulate the fact that the hatch only has a very small resistance
to blowing open. And we'll be looking for differences in the damage patterns
between the surface submarine and the sunken submarine.

DAVID LORING: We're going to be utilizing underwater explosive, C4.
We're going to place it inside the sub, in the approximate location that the
scuttling charges are placed, which is in this area here.

NARRATOR: The first experiment will replicate a scuttling
charge with the midget sub surfaced.

BRIAN HOPKINS (United
States Navy): Fire in the hole!
Fire in the hole! Fire in the hole!

NARRATOR: The first result is disappointing. It doesn't
match the damage discovered under water.

ROGER LONG: It doesn't look anything like the one we're thinking
about.

NARRATOR: The team decides to experiment with a slightly
larger charge.

BRIAN HOPKINS: Fire in the hole!

PARKS STEPHENSON: We're
going to need another tank.

NARRATOR: Whether the charge is large or small, it appears
that midget sub number 5 was not scuttled on the surface.

A
new tank is prepared, and the replica of the midget sub is secured to the
bottom.

ROGER LONG: Next, we want to replicate the other surface model
with a smaller charge—exactly the same charge, but at the bottom of that
tank over there, so we can see what happened if it exploded on the bottom.

BRIAN HOPKINS: Fire in the hole!

ROGER LONG: The damage is a lot more similar to the Pearl Harbor
sub, which leads me to think that the scuttling charge was set off with the sub
on the bottom, not on the surface.

NARRATOR: The demolition team concludes that the sub was
scuttled under water, which implies the remains of the crew are still inside.

But none of this explains how midget sub number 5
wound up in three pieces, at the bottom of the ocean, several miles outside
Pearl Harbor.

During the underwater investigation, three
mysterious cables were found attached to all three pieces of the submarine.

For a salvage diver like John Chatterton, this
can only mean one thing.

JOHN CHATTERTON: My
best guess is that this submarine was salvaged, it was brought up, put on some
kind of platform. It was cut apart. The three sections were taken apart, and
then they were taken out and dumped.

NARRATOR: But who dumped it and why?

John Chatterton joins Parks Stephenson for a
closer look at the West Loch, where the team believes midget sub number 5 was
scuttled.

JOHN CHATTERTON: What
do we have over here, Parks?

PARKS STEPHENSON: Well
this is the Waipio Peninsula, its largely un-inhabited peninsula, part of the naval
reservation. Back in 1941, it was covered with sugar cane fields. But this is
the entrance to the West Loch.

NARRATOR: And then they see it, the final clue, hidden in
plain sight.

PARKS STEPHENSON: Now,
what we're approaching here is the wreck of the L.S.T. 480.

NARRATOR: An L.S.T. It stands for Landing Ship, Tank.

These are naval vessels built to carry troops,
cargo and tanks directly onto shore.

The area surrounding the wreck of midget sub
number 5 is littered with the landing craft the L.S.T.s carried.

PARKS STEPHENSON: When
we were searching for the midget sub pieces, we ran across numerous damaged
amphibious track vehicles.

TERRY KERBY: Oh, no, this is another landing craft, a different
one. Ah, they're all over the place.

NARRATOR: But why are they here?

Turns
out Pearl Harbor suffered more than one unexpected disaster on a Sunday
morning. It took place three years later, on May 21st, 1944.

Unlike December 7th, this second disaster is not
well known, because, until recently, it was veiled in secrecy. As the Navy
prepared for the invasion of the Pacific island of Saipan, a terrible explosion
claimed the lives of almost 200 people in the West Loch.

PARKS STEPHENSON: There
was an accident in the ammunition handling being loaded aboard the L.S.T. 353. The
explosion spread from L.S.T. to L.S.T., sank six L.S.T.s, killed a couple
hundred sailors, wounded hundreds more.

NARRATOR: The invasion needed to get back on track, so the
West Loch was cleaned up quickly and quietly. The remnants of the disaster that
could be raised were hauled outside the harbor and dumped.

But along with the damaged equipment, it appears
the Navy may have also scooped up midget sub number 5, long after it was scuttled
in the West Loch.

PARKS STEPHENSON: It's
my contention that during that clean up, they found our midget sub. They raised
it, they put it in with the rest of the debris and took it out there and dumped
it all together.

NARRATOR: Perhaps that's why it now lies amidst an
assortment of U.S. military hardware from the West Loch disaster, three miles
outside Pearl Harbor, a thousand feet at the bottom of the sea.

Today Admiral Ueda visits the wreck of midget sub
number 5 to honor the remains of pilot Sadamu Kamita and commander Masaji
Yokoyama.

NARRATOR: A cup full of sand is carefully removed from the
seafloor, beneath the sealed control room of the midget sub, and given to
Admiral Ueda to take home.

AKIRA IRIYE: The
remains or the spirits of the dead, ah, from the submarine would now be
reunited with the sand.

NARRATOR: Admiral Ueda presents the sand to Petty Officer
Dewa.

He brings it to a memorial service for Japanese
sailors who lost their lives in midget submarines.

AKIRA IRIYE: The
sand that was brought back from Hawaii is purified now, becomes Japanese soil,
so to speak.

NARRATOR: For Kichiji Dewa, the mission is at last over.
For Parks Stephenson, it's always been about bringing the facts to light.

PARKS STEPHENSON: I
want their accomplishment known, so that their sacrifice will have meaning.

NARRATOR: Time may yet uncover new details in the history
of Pearl Harbor. And each step we take towards the truth of the heroic and
tragic events of that day, not only honors the people who lived it, but serves
future generations, as the real story is finally revealed.

WWII: Valor in the Pacific National Monument, Photo Archive
Japanese Midget Submarine Association
The National Archives
National Park Service
Hawaii Undersea Research Laboratory, University of Hawaii
U.S. Navy — Submarine Force Museum
UCLA Film & Television Archive

National corporate funding for NOVA is provided by Cancer Treatment Centers of America.
Major funding for NOVA is provided by the David H. Koch Fund for Science, the Corporation for Public Broadcasting, and PBS viewers.